Fuji Electric FRENIC-HVAC User Manual page 732

[ 3 ] Noise prevention examples
Table A.2 lists examples of the measures to prevent noise generated by a running
inverter.
Table A.2 Examples of Noise Prevention Measures
Target
No.
device
1 AM When operating an inverter,
radio noise enters into an AM
radio broadcast (500 to 1500
kHz).
<Possible cause>
The AM radio may receive
noise radiated from wires at
the power supply and output
sides of the inverter.
2 AM When operating an inverter,
radio noise enters into an AM radio
broadcast (500 to 1500 kHz).
<Possible cause>
The AM radio may receive
noise radiated from the power
line at the power supply side
of the inverter.
App. A Advantageous Use of Inverters (Notes on electrical noise)
Phenomena Noise prevention measures
1) Install an LC filter at the
power supply side of the
inverter. (In some cases, a
capacitive filter may be
used as a simple method.)
2) Install a metal conduit
wiring between the motor
and inverter.
Note: Minimize the distance between
the LC filter and inverter as short as
possible (within 1 m).
1) Install inductive filters at
the input and output sides
of the inverter.
The number of turns of
the zero-phase reactor (or
ferrite ring) should be as
large as possible. In
addition, wiring between
the inverter and the
zero-phase reactor (or
ferrite ring) should be as
short as possible. (within
1 m)
2) When further
improvement is necessary,
install LC filters.
A-9
Notes
1) The radiation
noise of the wiring
can be reduced.
2) The conduction
noise to the power
supply side can be
reduced.
Note: Sufficient
improvement may
not be expected in
narrow regions such
as between
mountains.
1) The radiation
noise of the wiring
can be reduced.